Various abbreviations that appear in the specification and/or in the drawing figures are defined as follows:    BS base station    RS relay station    QoS quality of service    SIR signal to interference ratio    UE user equipment
Most existing and standardized systems have been designed for bidirectional communication between a central BS and a UE directly linked to the BS. Relaying is generally considered as a method to ensure capacity improvement and coverage extension in cellular systems. The additional communication traffic between a mobile station and a relay intermediately inserted into a link between a remote UE (R-UE) and the BS requires additional considerations regarding the uplink signaling transmission.
Typically in relay networks there are two main scheduling modes that can be used, i.e., centralized and distributed scheduling modes. General reference in this regard may be made to IEEE P802.16j/D6, Draft Amendment to IEEE Standard for Local and Metropolitan Area Networks, Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Multihop Relay Specification, 2008-07-23. For the centralized scheduling mode the BS determines the bandwidth allocations for all the links (access and relay) in the cell. Thus, before a UE can transmit a packet to the BS, the bandwidth request of the UE needs to first reach the BS, which then creates the bandwidth allocations on the links along the path from the UE to the BS. For the distributed scheduling mode each BS and relay station (RS) individually determines the bandwidth allocations on the associated controlled links, and creates its own local resource allocations reflecting these decisions.
The distributed scheduling mode typically has less signaling overhead associated therewith, and further has the capability to respond more rapidly to channel variations that the centralized scheduling mode, and is thus desirable for use in a mobile relay network.
In those relay networks that operate with the centralized scheduling mode a RS forwards all bandwidth requests to the BS. The RS is defined so as to not combine bandwidth request amounts from different sources, since the BS preferably needs to have knowledge of the details of each bandwidth request in order to assign the uplink bandwidth along the proper route. As a result the BS is aware of the bandwidth request and bandwidth allocation of each node under its control.
In those relay networks that employ the distributed scheduling mode the RS may receive the bandwidth requests from its subordinate stations, and it may combine the bandwidth requests that arrive from the subordinate stations together with the bandwidth needs of queued data packets into one bandwidth request per QoS class. A given RS can then transmit an aggregate or incremental bandwidth request to a superordinate station (a RS in the path that is closer to the BS). Consequently, the BS is only aware of the bandwidth requests from its subordinate stations, and is not aware of the bandwidth requests originating from individual sources. That is, the BS is not aware of the bandwidth requests and bandwidth allocations of those nodes that are not the direct subordinates of the BS.